Four of the component studies of the Program Project in Human Development and Aging were terminated in December 1978. The ongoing Longitudinal Study of Transitions is an investigation of the dynamics of psychosocial change and adaptation across the adult life course, the changes examined within the context of normative life transitions. The parameters include: values, commitments, and activity patterns; the social system, examined in terms of social roles, intra- and extra-familial relationships, social networks and social attitudes; the personal system, with emphasis on personality characteristics and self-concept; the adaptive domain, examined in terms of psychological resources and deficits, modes of emotional experiencing, and coping styles; and stress experience. The objective is to determine the relative contribution of social, psychological and situational factors to personal growth and adaptation at successive stages of the life course, with particular emphasis to stage-specific, situational, and sociocultural stresses, and the comparative effectiveness of coping styles. The theoretical framework includes innovative analytic models of stress, adaptation, transitions, and commitments. The middle and lower middle class Anglo-American sample (N equals 216) consists of men and women representing four pretransitional life stages: high school seniors, newlyweds, empty-nest parents, and preretirees. The research design combined qualitative and quantitative techniques and included an intensive baseline interview at the pretransitional stage and 3 follow-ups across a 7-year period to evaluate the processes and outcomes of the respective transitions.